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FARS Auxiliary Files
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The FARS Auxiliary files are datasets that are derived from the standard FARS datasets: 
1. Accident -> Acc_Aux
2. Vehicle -> Veh_Aux
3. Person -> Per_Aux
These files are joined by the standard key variables.
Please read the following document for additional details: http://www-nrd.nhtsa.dot.gov/Pubs/811364.pdf
For User Manuals, please go to: ftp://ftp.nhtsa.dot.gov/FARS/FARS-Doc/FARS_Auxiliary_Analytical_User_Manuals.zip
For SAS Format Catalog, please go to: ftp://ftp.nhtsa.dot.gov/FARS/Auxiliary_FARS_Files_Formats

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#   Update Notes  #
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07/07/2017: files are released with FARS 2016 annual data.
09/27/2018: files are released for FARS 2016 final data.Starting from 9/27/2018, there are 2 zip files for two different file formats in each folder: SAS and CSV.  NHTSA discontinued supporting for DBF format.
10/22/2019: This is an updated FARS 2016 final data. The followings were updated:
   1.	Corrected BAC and Roadway data for North Carolina
	+ REVISED ALCOHOL TEST STATUS, TEST TYPE AND TEST RESULTS BASED ON INFORMATION FROM THE NC OFFICE OF THE CHIEF MEDICAL EXAMINER; 
	+ REVISED TRAFFIC ID 1 & 2 TO SEPARATE NORTH CAROLINA STATE ROUTES FROM SECONDARY STATE ROUTES.  
		- SECONDARY STATE ROUTES PRE-FIXED BY SSR-.  
		- NORTH CAROLINA ROUTES REMAIN PRE-FIXED BY SR-.  
		- SECONDARY STATE ROUTE ROUTE SIGNING REVISED TO 8-OTHER, FUNCTIONAL SYSTEM, NHS AND MILE POINT REVISED ACCORDING TO NC DOT ROADWAY INVENTORY USING NC DOT  SPATIAL DATA VIEWER; 
   2.	Updated vehicle body type and GVWR information. 
	+ REVISED BODY TYPE TO CORRESPOND TO GVWR INDICATED BY DECODED VIN; 
	+ REVISED MOTOR CARRIER IDENTIFICATION NUMBER, GVWR/GCWR, VEHICLE CONFIGURATION AND CARGO BODY TYPE TO CORRESPOND TO THE REQUIREMENTS OF CODING MEDIUM/HEAVY BODY TYPES

10/30/2019: acc_aux file is updated for National CSV and SAS zip files. 
08/14/2020: The National accident.csv file has been updated for the variable "Longitute" precision from 4-digit to 8-digits.
12/18/2020:
   1. ACCIDENT SAS file is updated to include STATENAME, COUNTYNAME and CITYNAME.
   2. VEHICLE files: Florida Case #918 Vehicle #2: UNDERRIDE/OVERRIDE value is changed from 0 to 1-Underride (Compartment Intrusion).
   3. ACCIDENT files are updated for Maine Case #136.  The CITY code was erroneously entered as 3700 (HOLDEN) instead of 0850 (BREWER).
   4. Starting from this file release, the CSV files contain the (ID, TEXT) value for look-up data variables.
   5. Starting from this file release, VINDecode files are not published any more.
03/02/2022:
   1. Publish VPICDECODE and VPICTRAILERDECODE files. These files are created using NHTSA's vPIC tool and contains the vPIC decode results for cleanly decoded VINs. 
      For detailed information about this file, please refer to "Product Information Catalog and Vehicle Listing (vPIC) Analytical User's Manual, 2020" 
   2. PER_AUX, VEH_AUX and ACC_AUX files are updated
   3. Starting from this file release, the FARS file directory structure has been changed beginning 1982. 
	Auxiliary files are zipped separately from the rest of the FARS files. 
	For each year, there are two folders, one for national and one for Puerto Rico. 
	In each folder, there are four zip files 
		- one zip file for Auxiliary SAS files 
		- one zip file for Auxiliary CSV files
		- one zip file for non-Auxiliary SAS files
		- one zip file for non-Auxiliary CSV files